ABSTRACT
This chapter focuses on characteristic of spatial data that is rooted in the need to aggregate geo-referenced data in order to make them manageable and to uncover pattern. The term 'modifiable areal unit problem' was first coined by Openshaw and Taylor when they rediscovered a particular type of spatial dependency latent in geo-referenced data. The chapter discusses the source of modifiable areal unit problem (MAUP), the impacts of the problem, solutions that have been proposed, and conditions under which the MAUP should be acknowledged. Many studies have sought to determine when MAUP becomes important, and have verified that the first law of geography (i.e. closer objects are more similar than distant objects) is the source of the problem. When aggregation of areal units is performed in a noncontiguous or spatially random fashion, MAUP does not exist. The chapter discusses the nature of the MAUP, with specific emphasis on the scale effect.
